Question: Ben, Cam, and Justin are lumberjacks. The number of trees they chop down is given by $b+2c+3j$ where $b$ is the number of hours Ben spends chopping, $c$ is the number of hours Cam spends chopping, and $j$ is the number of hours Justin spends chopping. How many trees do they chop down after Ben spends $8$ hours chopping, Cam spends $3$ hours chopping, and Justin spends $4$ hours chopping?
Explanation: Ben chopping for $8$ hours, Cam chopping for $3$ hours, and Justin chopping for $4$ hours tells us that $b={8}$, $c={3}$, and $j={4}$. Let's substitute $b={8}$, $c={3}$, and $j={4}$ into the expression and evaluate: $\begin{aligned} &\phantom{=}b+2c+3j\\\\ &= {8}+2({3})+3(4)\\\\ &= 8+6+12\\\\ &= {26} \end{aligned}$ They chop down a total of ${26}$ trees after Ben spends $8$ hours chopping, Cam spends $3$ hours chopping, and Justin spends $4$ hours chopping.